1. Field of the Invention
The present invention generally relates to a portable telephone apparatus. More specifically, the present invention is directed to a portable telephone set including an electronic notebook function capable of registering a plurality of telephone directory data. So-called "telephone directory data" is constructed of one set of name data and telephone number data.
2. Description of the Prior Art
Various types of portable telephone sets or apparatuses have been widely marketed due to convenient functions thereof, for instance, everywhere and every time a telephone conversation is available. However, it is practically difficult for every one to correctly remember a large number of telephone numbers of friends, business partners, and community members etc. In a specific case, even if surnames or titles of firms are clearly memorized, last names or names of departments could not be correctly found out. To avoid such a problem, other types of portable telephone sets are very recently commercially available, in which a plurality of so-termed "telephone directory data" arranged by a pair of name data and telephone number data can be registered. In this typical conventional portable telephone set, 10 numeral keys of dialing are utilized as keys for entering character data required to register these names and titles.
However, even when an alphabetic character is employed which needs a smaller character number than other characters, there are approximately 40 sorts of key input data, namely 10 sorts of numeral data, 26 sorts of character data, and several sorts of symbol data. As a consequence, the respective numeral keys used for the dialing function must have 4 or more sorts of key functions. For instance, the numeral key "1" owns 4 different key functions to enter numeral data "1", character data "A", "B" and "C". On the other hand, the above-described conventional portable telephone set is equipped with the data input mode switch for selecting the numeral data input mode and the character data input mode. When, for example, the character data "C" is inputted, even if the character data input mode has been selected by operating the data input mode switch, the key for shifting the input digit must be manipulated after the numeral key "1" has been operated three times. In other words, the conventional portable telephone sets have such a drawback that the key operation must be performed at least four times, depending upon sorts of characters, namely a very cumbersome data input operation is necessarily required.
The present invention has been made in an attempt to solve the above-described drawback, and therefore, has an object to provide a portable telephone apparatus including an electronic notebook function, capable of simply dialing and also of simply performing a data input operation such as a telephone directory data entry operation.
Another object of the present invention is to provide a portable telephone apparatus including an electronic notebook, capable of automatically selecting a telephone mode and an electronic notebook mode. In the telephone mode, a dialing operation is available, whereas in the electronic notebook mode, a data input operation is available.
A further object of the present invention is to provide a portable telephone apparatus including an electronic notebook function, capable of searching data about the electronic notebook in a telephone mode.